The site that had NEWS' countdown clock on 12AM JST revealed silhouettes of the four members of NEWS and a short music clip, which if you listen to closely says "NEWS is back." As this was revealed for fans to see the site apparently crashed but it did let some see more, as in a a version with the members of NEWS not blacked out.
No other confirmed information is out, other than most are suspecting that the special announcement on K-chan no NEWS will be to confirm a new release from the group. We will have to wait until Tuesday when it airs to find out.
Otherwise there are rumors that the new release will be a new single and a Best album.
Personally I am not sure if I would care for a Best album unless all the songs on it were re-recorded with only the current members of NEWS. I think if they were to start a new era with these four it should be a clean break from the previous six member NEWS. But as it is all rumor now I will not worry too much about it. Hopefully everything clears up on the 17th when the guys make their announcement.
As things stand now the guys are finally back and ready to start NEWS activities and so is Johnny's. That for right now that is what matters most for me.